"William C. (Bill) Johnson" <ez003195 at peseta.ucdavis.edu> writes:
>General question - how long do most antibiotics retain their effectiveness?
>>Specifically - how useful is, say, the four year old tube of ampicillin I
>found in the -20 freezer? I've been told that most antibiotics in an
>agar plate are only good for a few weeks, and now I wonder about our stocks.
>>Thanks
Freezer stocks are usually good for up to six months at -20, one year at -80.
At least this is the guidelines we've been using. You may want to try pouring
a couple of plates with your old amp and see whether amp sensitive bacteria
will grow.
Cheers,
Emmanuel
_______________________________________________________________________________
Emmanuel Skoufos, Ph.D.
Insect Molecular Biology Group
Institute of Molecular Biology and Biotechnology
Box 1527
Heraklion, Crete 71110
Greece